This invention relates to an intake system for an internal combustion engine and more particularly to an improved, compact and high efficiency intake system for an internal combustion engine that improves the running of the engine throughout its entire load and speed ranges.
In copending application Ser. No. 845,576, entitled "Intake System For Internal Combustion Engine", filed Mar. 28, 1986 in the names of Manabu Kobayashi, Kazutoshi Suzuki and Takeo Kondo, and assigned to the assignee of this application, still pending, there is disclosed an induction system for an internal combustion engine that is designed to provide improved running through the entire engine load and speed ranges. This is achieved by providing, in essence, two separate induction systems for each chamber of the engine. One induction system is relatively long and may be tuned for good low speed running while the other is relatively short and is tuned for good high speed running. A throttle valve arrangement is incorporated so as to insure that the proper induction system serves the combustion chamber under all running conditions. Each induction system is provided with its own plenum chamber and a separate atmospheric air inlet is provided to each plenum chamber. Although this type of induction system well achieves the desired results, the use of two separate plenum chambers and two separate air intakes requires the use of two separate air filters and thus can substantially increase the size of the engine and particularly its intake system. In addition, this provides servicing difficulties for the owner since the owner must service two air filter elements.
It is, therefore, a principal object of this invention to provide an improved induction system for an internal combustion engine that will improve performance throughout the entire speed and load ranges and which is, nevertheless, compact.
It is a further object of this invention to provide a high efficiency induction system for an internal combustion engine having a dual intake device which necessitates only a single air cleaner and air inlet.